The time required to bring a train to a stop subsequent to initiating an emergency brake application thereon is dependent upon both the speed and the weight, and therefore the length, of the moving mass. Usually the brake apparatus provided on a locomotive used to haul a long, heavy freight train at a comparatively low speed is substantially the same as that provided on a locomotive used to haul a short train, such as a passenger train, at a high speed. Therefore, it is apparent that the addition of a simple and inexpensive means to the presently provided locomotive brake apparatus whereby the time between the initiation and subsequent release of an emergency brake application may be selectively increased or decreased as desired would be most welcomed by the railroad industry.
Moreover, certain railroads, in making up a train of cars, may put most or all of the empty cars in the front half of the train next to the locomotive and most or all of the loaded cars in that half of the train that is most remote from the locomotive. These empty cars in the front half of the train are provided with a higher braking ratio than the loaded cars in the remainder of the train. Therefore, whenever an emergency brake application is effected, as a result of a break-in-two of the train, these empty cars are decelerated at a faster rate than the loaded cars. Accordingly, it is apparent that these loaded cars will collide with the empty cars so that these loaded cars may possibly cause damage to the empty cars nearest the locomotive if this collision is too severe. It is apparent that this impact of collision, subsequent to a break-in-two of the train, could be reduced if the brake application were promptly released on that portion of the train between the point of break-in-two and the locomotive. Hence, it can be appreciated that these certain railroads that operate trains having a number of empty cars in the first half of their trains and a number of loaded cars in the remainder would look with favor upon any simple and inexpensive addition to presently used brake apparatus that enables a reduction in the time between initiating an emergency brake application and the subsequent release thereof whereby, upon the occurrence of this brake release on the empty cars in the front half of the train, the locomotive would be rendered effective to pull these empty cars away from the loaded cars thereby reducing the impact of collision and therefore, the possible damage resulting therefrom.
Accordingly, it is the general purpose of this invention to provide, by the addition of simple and inexpensive devices to presently used locomotive brake control apparatus, for either increasing or decreasing, as desired, the time between the initiation and subsequent release of an emergency brake application on a locomotive and a train of cars hauled thereby.